Stroke is the leading cause of disability in the US, with 795,000 Americans suffering one each year. See Reference No. 1. (all references are listed at the end of the specification). Traditional physical rehabilitation of the paretic arm involves passive movement, compensatory training on the less involved arm, electrical stimulation, to which more recently has been added constraint induced therapy to combat learned non-use of the hemiplegic hand. See Reference No. 2. These are uni-manual training approaches involving a single arm which do not take into account the prevalence of activities of daily living (ADLs) which involve both arms.
Another drawback of uni-manual training is diminished neural cross talk to mirror motor areas associated with bimanual activities. A meta analysis of 48 stroke studies to determine the cumulative effect of bilateral arm training on motor capabilities post-stroke (Reference No. 3) did however find a significant effect post training involving bimanual repeated reach movements timed to auditory cues. Another argument in favor of bilateral training is a randomized controlled study of stroke patients at the end of their outpatient therapy. See Reference No. 4. Researchers found, for the first time, that training the healthy arm (in a peg-board filling task) resulted in a 23% functional improvement in the non-trained paretic arm. Researchers also observed improvement in bilateral tasks performance in the experimental group. The control group, which did not train, had no significant difference from baseline. These studies point to the untapped advantages of bimanual training and motivate the present application.
It is known in the art that numerous task-related repetitions are needed to produce changes in the brain. Repetitions, while necessary to induce recovery through brain plasticity, can lead to lack of engagement (attendance to task) by the patient. Second only to the amount of practice, feedback on performance is a key element in motor training and a way to engage the patient. Knowledge of performance feedback can be provided by the therapist (present next to the patient), or through graphics in a virtual rehabilitation setting (Reference No. 5), where the therapist may be remote. Virtual rehabilitation benefits focus, motivation, and provides substantially more intensive training than customary care.
Stroke survivors, as well as other patient populations (such as those post severe traumatic brain injury) present with both motor and cognitive deficits. See Reference No. 6. Typically their short term and long term memory are affected, as are decision making (executive function), and the ability to focus. Most stroke patients also get depressed. Under the current fractionated care system, such patients are attended by therapists, as well as psychologists or psychiatrists, in separate sessions. This care delivery method is costly and does not exploit fully the body-mind continuum. As opposed to patients who are post-traumatic brain injury and predominantly young, the elderly form the majority of stroke survivors. For them, the situation worsens due to age related cognitive decline. See Reference No. 7. One age related cognitive deficit is associated with diminished ability for split attention (or dual-tasking). These patients need a system designed from the start for integrative cognitive and motor therapy, in order to minimize costs and maximize outcomes. Such system would use therapeutic games that pose both cognitive and whole arm motor demands, and train grasping in dual tasks. The system should automatically adapt to the patient's functioning level, thus making games winnable, so to improve morale (reduce depression). Games, such as cognitive games, mediate many repetitions, so to facilitate improvement or at least maintenance of motor and cognitive function over time. Users that benefit most are the elderly with mild cognitive impairment (MCI) developing into dementia (Reference No. 8).
There are indications that bimanual training induces higher functional improvements compared to uni-manual training. A randomized controlled study (Reference No. 9) was performed on patients who were chronic post-stroke, half doing bimanual training and the controls doing training of the affected arm, with some coping mechanism (assistance) from the other arm. While both groups had the same training duration and intensity, those doing bimanual training had a 9 points larger improvement in motor function (as measured by their Fugl Meyer Assessment [Reference 10] scores) vs. controls. Another randomized study of 36 nursing home residents was performed to try to lessen cognitive decline and improve memory function. See Reference 11. The experimental group showed significant improvements in long-term recall and in several other aspects of cognition, while controls showed progressive decline. The above findings motivate the system described here, a bimanual therapy system that simultaneously addresses motor and cognitive impairments of patients post-stroke, post TBI, or those with MCI developing into dementia. This novel integrative therapy uses custom, adaptable, bimanual virtual reality games, which combine into gradated therapy sessions.